Intelligent Optical Systems (IOS) Inc., in collaboration with Dr. Jozsef Gabor of the University of Southern California (USC) Radiation Oncology Department, proposes to demonstrate, for the first time the feasibility of a multipoint fiber-optic radiation dosimeter probe having a diameter smaller than a French 1 catheter (less than 333micromoles). IOS's optical fiber dosimeter will open up new possibilities for accurate monitoring of actual dose in several in-vivo dosimetry (IVD) applications that are presently hindered due to the size constraints of existing sensors. This device will be especially suited for brachytherapy applications. Contrary to existing diode based dosimeters, which require constant calibrations IOS's multipoint dosimetric system will operate in an automatically calibrating mode that will greatly facilitate its clinical use. PROPOSED COMMERCIAL APPLICATIONS: A wide range of in-vivo dosimetric applications exist where available sensors are incapable of being used due to their larger size. Primary applications include dosimetry in the brachytherapy of interstitial cavities, for actual quantification of applied dose. Actual real-time in-vivo dosimetry will permit accurate control and localization of the therapeutic dose and avoid unwanted radiation overexposure.